Surely you aren't expecting to win the prize for free!!!

This number would be classed here as justified. They are offering a service that you do not need, it is a luxury that you choose to ring for.
This number provides a solution or further clues to the crossword in todays paper.

If it was a utility company or a helpline ( as in "Your product has broken, how are you going to fix it for me") then help would be offered because these numbers are a necessity. Just to know that 3 across is "rabbit", and that you would have got the answer tomorrow, is not a necessity but is a service